Q. Are liquids and gels permitted in my checked baggage?
A. Yes. The new rules only apply to carry-on baggage.

Q. May I bring liquids and gels in my carry-on?
A. Yes, but only in limited amounts. Liquids and gels must be in individual containers of three ounces or less and placed inside one clear, quart-size, plastic, zip-top bag. The TSA emphasizes that containers should fit comfortably into your bag, and that only one bag is permitted per passenger. If you need to bring more than three ounces of any liquid or gel substance, it should go into your checked luggage.

Q. What about prescription medications, baby formula or milk?
A. These substances are exempt from the rules above. As long as you declare them at the security checkpoint, you may carry more than three ounces, and they do not need to be placed in a plastic bag. The TSA recommends but does not require that prescription medications be in their original labeled containers to expedite the screening process. The TSA may also make exemptions for other medical necessities such as insulin, eye drops or syringes; see the TSA Web site for more details.

Q. Do solid vitamins and medications need to be packed in their original containers?
While the TSA encourages travelers to keep their medications and vitamins in their original labeled containers to expedite the screening process, you may transfer them into more convenient smaller containers such as daily pill minders.

Q. What about makeup?
A. Makeup is subject to the same liquid and gel rules as all other substances -- so if you're bringing liquid mascara, lip gels (such as Blistex) or other liquid- or gel-like items, they will need to be placed in your quart-size plastic bag in three-ounce or smaller containers. Lipstick, powders, solid lip balms (such as Chapstick) and other solid beauty products are not subject to the rules and may be carried in your hand luggage without restriction.

Q. What about food?
Even though the TSA says to "try not to over-think" the new guidelines, that can be tricky when it comes to food items. Does a cheesecake count as a gel or a solid? What about pecan pie? And can you bring your holiday leftovers like turkey, stuffing and mashed potatoes?

A TSA said that turkey and stuffing should be solid enough to pass muster, but mashed potatoes are a bit too gel-like. As for baked goods, the latest word from the TSA is that travelers can take pies, cakes and other bakery products through security, but they should be prepared for random additional screening. Similarly, you can bring solid snack foods such as pretzels, potato chips or carrot sticks for the plane -- but you may want to hold the peanut butter and jelly sandwich.

Single serving packages of condiments are permitted as long as they fit within your single zip-top bag, so you can add mustard to your ham sandwich after you get through security. All food must be securely wrapped or in a spill-proof container. You may not bring gel packs to refrigerate food (though they are permitted for medication).

Advice? If you have any doubts about an item, either check it or leave it at home. After all, you may buy food or drinks after you pass through the security checkpoint if you need some munchies for the plane.

A. Yes.

Q. Are there any special rules for batteries?
As of January 1, 2008, loose lithium batteries are no longer permitted in checked bags. If your batteries are installed in a device (such as a camera), you may pack the device in either a checked bag or a carry-on, but loose lithium batteries may only be transported in your carry-on luggage. Certain quantity limits apply to both loose and installed batteries; for more information, see the Department of Transportation's Web site.

Q. What if I'm traveling internationally?
A. The European Union (E.U.) as well as other countries such as Australia, Japan, Singapore, Iceland and Norway have adopted similar security restrictions to those in the U.S. You are permitted 100-milliliter containers of liquid and gel substances, packed within a clear, resealable, one-liter plastic bag. More on Australia's rules can be found here. More on the European Union's policies can be found here.

Q. Am I permitted to bring duty-free liquids in my carry-on bags?
Duty-free liquids, such as perfume or alcohol, are subject to the same rules as all other liquids and gels when it comes to U.S. security checkpoints -- containers must be no larger than three ounces, and they must fit into your clear, quart-size, plastic zip-top bag. That means that if you have a connection in a U.S. city before reaching your final stop, you must use your time in customs to put your duty-free items into your checked baggage.

The same rules apply to the security checkpoints in the European Union and other nations mentioned above, with one exception: duty-free items purchased in airports in those countries will be given to you in special tamper-evident bags, which may be safely taken through airport security checkpoints in those countries. However, the tamper-evident bags will not pass muster in the United States, so you must transfer the items into your checked baggage while you're in customs. For more information, see the TSA's tips and rules on duty-free items.

Q. May I bring dry ice in my carry-on? What about my checked bags?
The Department of Transportation has strict regulations about the transportation of dry ice on airplanes. As long as you comply with those regulations, you may pack dry ice in your checked bag. A DOT spokesperson suggests that travelers avoid packing dry ice in carry-on luggage, as individual TSA agents unfamiliar with DOT regulations may confiscate the substance.

Q. How early should I arrive at the airport?
A. We recommend arriving at the airport two hours before your flight, especially if you're traveling during the summer, the holidays or another particularly busy time of year. If you're flying internationally, you should allow yourself even more time.

Q. What should I expect at the security checkpoint?
A. You will have to put all footwear, jackets, jewelry, cell phones, keys and other metal items into a bin for screening before you step through the metal detector. Laptops and video cameras must be removed from their cases and screened individually. You can save time at the checkpoint by putting all metal items into your carry-on ahead of time, taking your electronic items out of their cases before reaching the security checkpoint, and wearing easily removable footwear.

Q. I'm bringing birthday or holiday gifts. What's the best way to pack them?
A. Do not pack wrapped gifts in either your carry-on or checked baggage, as the TSA may have to unwrap them for inspection. Your best bet is to wrap your gifts once you arrive at your destination, or ship them ahead of time.

Q. May I bring electronic items on the plane or in my checked luggage? If so, how should I pack them?
Laptops, video cameras, iPods, Gameboys and most other standard electronic devices are permitted in both checked and carry-on luggage. As noted above, you should be prepared to remove laptops or video cameras from their cases at the security checkpoint for additional screening. Because electronic items tend to be frequent targets for security screening, you may want to pack these near the top of your bag so that inspectors don't need to unpack your whole suitcase to get to them.

Keep in mind that certain electronic devices -- such as radios, cordless computer mice or portable GPS systems -- may not be used in flight even if you do pack them in your carry-on, as they may interfere with the plane's navigational or communications systems.

Q. Can I lock any suitcases that I'm checking?
A. Yes, but you'll need to use a TSA-approved lock so that screeners can open it if your bag is selected for inspection. TSA screeners will simply cut off non-approved locks if they need to get into your bag. You can learn more about approved locks and where to find them at the TSA's Web site.

Q. Where can I find more information about airport security?
A. Check the TSA's Web site for packing tips, a full list of permitted and prohibited items, and information for travelers with special needs.